Is secession not illegal, unconstitutional, and discredited?
By no means. Most of those who wrote and ratified the constitution recognised secession as a legitimate, legal, and constitutional measure of protection against the possibility that the national government might in the future consolidate and centralise power, violate the terms of the constitution, and usurp the rights and liberties of the people of the sovereign States. Secession is a right of a truly free people and the cornerstone of confederalism. What has been tried, failed, and discredited is centralism by unitary government that reneged on its original compact as an agent of the States, usurped their sovereignty, and opted instead to hold the ‘Union’ together by brute force.